Broussonetia papyrifera is a widely distributed economic tree species, and it is also a pioneer species in adverse environments. In order to investigate the growth and adaptation mechanism of B. papyrifera under cadmium (Cd) contaminated soil, potted experiments were used with six-month treatments to study Cd enrichment and the transportation, morphological and physiological characteristics of B. papyrifera tissues. The results showed that Cd mainly accumulated in the root when the Cd concentration was high (14.71 mg/kg), and the root biomass was significantly reduced by Cd stress although Cd promoted the growth of seedlings. The bioconcentration factors (BCF) increased with the increase in Cd concentration, and reached the maximum value of 0.21 at 14.71 mg/kg. On the contrary, translocation factor (TF) decreased significantly at 8.28–14.71 mg/kg Cd concentration. Cd not only led to the loose arrangement of the xylem vessels of leaves, but also changed the chlorophyll content. However, B. papyrifera could synthesize organic solutes such as soluble protein, soluble sugar and proline to reduce the intracellular osmotic potential. Our study proved that B. papyrifera has good tolerance to Cd stress and is a pioneer tree species for soil and ecological environment restoration.

Broussonetia papyrifera is an important ecological and economic tree species. The sexual reproduction of B. papyrifera not only has a low germination rate, but also requires high environmental conditions. Therefore, asexual propagation using tissue culture can effectively improve the propagation efficiency of B. papyrifera. In this study, the leaves and budded shoots of B. papyrifera were used as explants, and different concentrations of plant growth regulators were added to Murashige and Skoog medium (MS) to establish a suitable system for explant callus formation, adventitious buds differentiation and rooting. The results showed that MS + 0.50 mg/L naphthaleneacetic acid (NAA) + 0.25 mg/L 6-benzyladenine(6-BA) and MS + 0.25 mg/L NAA + 0.50 mg/L 6-BA were the best mediums for rapid callus induction from leaf explants and shoot explants, respectively. The best medium combination for shoot differentiation and proliferation was MS + 0.05 mg/L NAA + 0.50 mg/L 6-BA, and the high propagation coefficient could also promote adventitious bud growth. The best rooting medium in the establishment of B. papyrifera tissue culture was MS + 0.25 mg/L NAA. Under this condition, the average rooting numbers of leaf explants and shoot explants were 1.71 and 13.86, respectively. In addition, the best transplanting substrate was a mixture of soil:perlite:vermiculite (20:1:1), and the survival rate was 91.1%. This study established a propagation system in vitro culture of B. papyrifera, and provided a reference for tissue culture of other woody plants.